/*
 * Copyright � 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Reflection;
using Spring.Util;

namespace Spring.Objects.Factory.Support;

/// <summary>
/// An <see cref="Spring.Objects.Factory.Support.IMethodReplacer"/>
/// implementation that provides some convenience support for
/// derived classes.
/// </summary>
/// <remarks>
/// <p>
/// This class is reserved for internal use within the framework; it is
/// not intended to be used by application developers using Spring.NET.
/// </p>
/// </remarks>
/// <author>Rick Evans</author>
public abstract class AbstractMethodReplacer : IMethodReplacer
{
    private IConfigurableObjectDefinition objectDefinition;
    private IObjectFactory objectFactory;

    /// <summary>
    /// Creates a new instance of the
    /// <see cref="ArgumentNullException"/>
    /// class.
    /// </summary>
    /// <remarks>
    /// <p>
    /// This is an <see lang="abstract"/> class, and as such has no
    /// publicly visible constructors.
    /// </p>
    /// </remarks>
    /// <param name="objectDefinition">
    /// The object definition that is the target of the method replacement.
    /// </param>
    /// <param name="objectFactory">
    /// The enclosing IoC container with which the above
    /// <paramref name="objectDefinition"/> is associated.
    /// </param>
    /// <exception cref="AbstractMethodReplacer">
    /// If either of the supplied arguments is <see langword="null"/>.
    /// </exception>
    protected AbstractMethodReplacer(
        IConfigurableObjectDefinition objectDefinition, IObjectFactory objectFactory)
    {
        AssertUtils.ArgumentNotNull(objectDefinition, "objectDefinition");
        AssertUtils.ArgumentNotNull(objectFactory, "objectFactory");
        this.objectDefinition = objectDefinition;
        this.objectFactory = objectFactory;
    }

    /// <summary>
    /// Is <see lang="abstract"/>; derived classes must supply an implementation.
    /// </summary>
    /// <param name="target">
    /// The instance whose <paramref name="method"/> is to be
    /// (re)implemented.
    /// </param>
    /// <param name="method">
    /// The method that is to be (re)implemented.
    /// </param>
    /// <param name="arguments">The target method's arguments.</param>
    /// <returns>The result of the object lookup.</returns>
    public abstract object Implement(object target, MethodInfo method, object[] arguments);

    /// <summary>
    /// Helper method for subclasses to retrieve the appropriate
    /// <see cref="Spring.Objects.Factory.Support.MethodOverride"/> for the
    /// supplied <paramref name="method"/>.
    /// </summary>
    /// <param name="method">
    /// The <see cref="System.Reflection.MethodInfo"/> to use to retrieve
    /// the appropriate
    /// <see cref="Spring.Objects.Factory.Support.MethodOverride"/>.
    /// </param>
    /// <returns>
    /// The appropriate
    /// <see cref="Spring.Objects.Factory.Support.MethodOverride"/>.
    /// </returns>
    protected MethodOverride GetOverride(MethodInfo method)
    {
        return this.objectDefinition.MethodOverrides.GetOverride(method);
    }

    /// <summary>
    /// Helper method for subclasses to lookup an object from an enclosing
    /// IoC container.
    /// </summary>
    /// <param name="objectName">
    /// The name of the object that is to be looked up.
    /// </param>
    /// <returns>
    /// The named object.
    /// </returns>
    protected object GetObject(string objectName)
    {
        return this.objectFactory.GetObject(objectName);
    }
}
